The present invention relates to a backing plate for a railroad brake shoe.
Generally, the brake shoe has a backing plate made of metal which is mounted to the brake shoe material. The backing plate has a lug or key way slot within a lug section to permit the backing plate to be attached to a brake head. The brake head in turn is attached to a brake beam of a railroad car. After the brake shoe is attached to the brake head, it is positioned to selectively engage a wheel of the railroad car upon movement supplied by the brake head. Vibration and loading at the lug slot causes stress to occur at the lug section and causes weakening thereof. Brake failures occur when the lug section has been so severely weakened that it breaks apart.
Prior brake shoe art has tried to solve this problem by adding separate reinforcing structures to the lug section of the backing plate. Such structures are bonded, molded, clamped or inserted into the lug section. While these reinforcing structures provide addition strength to an unsupported lug section, the additional structures can create additional stress points. Moreover, testing has shown that a backing plate without a separate reinforcing structure is not as strong as a backing plate which has a reinforcing structure formed as an integral part thereof.
Specifically, where the integrally formed reinforcing structure was in the form of reinforcing ribs, the ribbed backing plate withstands intact up to 75 minutes of vibration with no signs of failure whereas the non-ribbed backing plates average 14 minutes before failing. The ribbed backing plate also has achieved stronger results in relation to deflection tests performed on a flat surface. In such tests, the ribbed backing plate required a force which is 21.6% larger than the non-ribbed backing plate in order to move the backing plate 0.06 inches downward. Thus, it is desirous to create a backing plate which incorporates a reinforcing structure as an integral part of the backing plate.
The present invention provides a backing plate for a railroad car brake shoe that has integrally formed reinforcing structures thus providing a reinforced backing plate formed as a single uniform piece.
The present invention relates to a backing plate for a railroad car brake shoe where a backing plate lug section has a reinforcing structure integrally formed therewith.
A primary purpose of the invention is to provide a backing plate for a brake shoe which incorporates reinforcing structures as part of the backing plate lug section thus forming a single reinforced backing plate.
Another purpose of the invention is to provide a stronger lug section for the backing plate which withstands greater stress and vibrational forces applied thereto.
Another purpose of the invention is to provide reinforcing structures for the backing plate in the form of reinforcing ribs formed within the lug section.
Another purpose of the invention is to provide a steel backing plate where the reinforcing structures are stamped into the steel backing plate thus making a one piece design without need for reinforcing inserts.